How do I solve LNK2019 for Direct3DCreate9?

Question

During compile time I get the following error:

RAT_RendererDX9.obj : error LNK2019: unresolved external symbol _Direct3DCreate9@4 referenced in function "public: void __thiscall RAT_ENGINE::RAT_RendererDX9::Init(class RAT_ENGINE::RAT_WindowManager *)" (?Init@RAT_RendererDX9@RAT_ENGINE@@QAEXPAVRAT_WindowManager@2@@Z)

The only place that I use Direct3DCreate9 is in my Init() function of the Renderer which has the following code:

void RAT_RendererDX9::Init(RAT_WindowManager* argWMan)
{
    wMan = argWMan;

    g_pD3D = (LPDIRECT3D9)Direct3DCreate9( D3D_SDK_VERSION );

    D3DPRESENT_PARAMETERS d3dpp;
    ZeroMemory( &d3dpp, sizeof( d3dpp ) );
    d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;

    g_pD3D->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,
                              D3DCREATE_SOFTWARE_VERTEXPROCESSING,
                              &d3dpp, &g_pd3dDevice );
}

Where does this error come from and how can I solve it?
I've tried the other answers to LNK2019, but they didn't resolve my problem.

Answer 1

I had to add the d3d9.lib file to my linker's additional dependencies, just like GSerg said.